I need to indexing the first character of a field in another field

[Renato Wesenauer]

Hello guys,

I need to indexing the first character of the field "autor" in another field
"inicialautor".
Example:
   autor = Mark Webber
   inicialautor = M

I did a javascript function in the dataimport, but the field  inicialautor
indexing empty.

The function:

    function InicialAutor(linha) {
        var aut = linha.get("autor");
        if (aut != null) {
          if (aut.length > 0) {
              var ch = aut.charAt(0);
              linha.put("inicialautor", ch);
          }
          else {
              linha.put("inicialautor", '');
          }
        }
        else {
            linha.put("inicialautor", '');
        }
        return linha;
    }

What's wrong?

Thank's,

Renato Wesenauer